The Big Bang Theory t-shirt "Four Hairlines" in light blue may keep your mom guessing, but The Big Bang Theory fans should get it. Wear this Big Bang Theory TV show shirt to class, confront your prof with "Bet you can tell who's who..." and see whether he aces it. This imported must-have The Big Bang Theory shirt and other The Big Bang Theory t-shirts come in comfortable 100% cotton and men's sizes small to XXL.